Answer:
3
Explanation:
- Each of the seven happy clowns has a red nose.
This means there are (15-7) 8 sad clowns.
- Five of the sad clowns have red noses.
This means out of 8 sad clowns, 5 have red noses. So the clowns that have to act sad and have red noses are (8-5) 3.